Conventional time keeping systems, such as clocks, usually require a variety of maintenance routines. The maintenance routines for power may include re-adjusting a pendulum in a gravity-powered time keeping system, rewinding a spring in a spring-driven time keeping system, or replacing batteries in a battery-powered time keeping system. Similarly, the maintenance steps for accuracy may include adjusting a display time periodically to properly display the current time, including advancing an hour during spring or retracting an hour during fall to compensate for the changes required by daylight savings time adjustment.
Many methods have been developed in an attempt to minimize, reduce, or eliminate these maintenance routines. For example, operating time keeping systems with electricity from a wall outlet or with solar cells may eliminate the power maintenance routine. Radio-controlled time keeping systems have also been developed to minimize or eliminate adjustment routines for accuracy and daylight savings time adjustment. However, these approaches add cost to the time keeping system, and restrict the areas or locations in which the time keeping system may operate. For example, a wall outlet must be available to use an electric time keeping system. Solar time keeping systems require a location with a significant source of light on a regular basis. Radio-controlled time keeping systems require locations in which radio signal reception is adequate. Therefore, a time keeping system whose operation is relatively independent of its placement whether for power or signal reception, and that still provides automatic time adjustment would be welcomed by users of time keeping systems.